Synthesis of dimaleimides

ABSTRACT

bifunctional maleimides can be prepared in high yield by reacting an organic diamine with maleic anhydride in a solvent composed of the azeotrope of hexamethylphosphoramide or 1-methyl-2-pyrrolidone and acetic acid, followed by dehydration of the intermediate with acetic anhydride in the presence of an alkali metal salt of a C 2  -C 5  aliphatic acid. The solvent systems are recoverable by reduced pressure distillation and can be used in subsequent syntheses of maleimides.



